Extensive experience with the diagnosis of childhood-onset schizophrenia indicates a high rate of false positives. Most mislabeled patients have chronic disabling, affective, or behavioral disorders. The authors report the cases of three children who passed stringent initial childhood-onset schizophrenia "screens" but had no chronic psychotic disorder. For two, the European literature yielded more fitting diagnoses: psychosis not otherwise specified (e.g., reactive or psychogenic psychosis, paranoid schizophrenia), single episode in full remission (e.g., anxiety psychosis), and factitious disorder (DSM-IV 300. 16). These cases illustrate that transient psychotic illnesses can be misdiagnosed as childhood-onset schizophrenia. Proper identification can prevent years of inappropriate therapies. J. Am. Acad. Child Adolesc. Psychiatry, 2004;43(8): 1026-1029. Key Words: childhood-onset schizophrenia, transient psychosis, brief reactive psychosis, anxiety psychosis, factitious disorder by proxy.